Hybrid powertrains have two or more power sources. Some hybrid vehicles are operable in an electric-only operating mode in which drive power is provided exclusively by one or more electric motor/generators that utilize power stored in an energy storage device (ESD) such as a battery. For hybrid vehicles that have an internal combustion engine as the other power source, operation in an electric-only mode improves fuel economy and reduces emissions. When the ESD is discharged to a predetermined level or when additional output torque is required, the engine is started. Starting the engine is typically accomplished using a dedicated starter motor or by engaging a clutch that directly connects the engine and the motor/generator, referred to as a starting clutch. Dedicated starter motors add weight and cost.